1. Field of the Invention
The invention relates to underwater arrays towed by submarines, and is directed more particularly to a normal belt capstan assembly for moving an array from a stowed location inboard of the submarine to a trailing condition outboard of the submarine, and for retrieving the array.
2. Description of the Prior Art
Underwater arrays 10 (FIG. 1) typically include a series of listening devices 12 mounted on a thin elongated cable 14. When not in use, the array is wound on a spool mounted on the submarine 16. When deployment of the array is in order, a capstan assembly, including a drive wheel and a number of spring-loaded rollers, is used to feed the array into the sea 18. The drive wheel and the rollers pinch the array and drive the array either onboard for storage or outboard for deployment.
The capstan assembly currently in use includes some seventeen spring-loaded rollers. Each roller applies about 15-20 pounds of force on the array and thereby on the drive wheel. The spring-loaded rollers maintain pressure on the array, and thereby the drive wheel, throughout operation of the capstan assembly. The capstan assembly is extremely expensive, 1-4 million dollars, depending upon the size of the assembly. The life spans of the current assemblies are relatively short, and the maintenance thereof requires about two man-days, a critical alignment exercise, and about $300 in consumable parts, per year.
Each array includes an array “termination”, an enlarged distal end portion of the array. Inasmuch as the termination portion of the array is of substantially larger diameter than the remainder of the array, and is of greater length than the array sensors, passage of the array termination through the capstan assembly is often problematic.
Thus, there is a need for an improved capstan assembly for deploying and retrieving underwater arrays, which assembly is more reliable, less expensive to buy and maintain, of greater life expectancy, and better able to handle array terminations without damage to the assembly or to the terminations.